The present invention relates to a novel security enclosure which may be used with an existing door frame.
Certain areas within a building or compound require security. In this regard, persons entering and leaving the security area must be controlled. Often security areas are designated to exist in standing edifices which are not originally designed as security spaces.
Second doors such as those shown in U.S. Pat. Nos. 617,308 and 4,302,689 have been designed to reduce heat loss from a building by forming a small chamber outside the door of the building. U.S. Pat. Nos. 1,960,578 and 2,076,765 describe protective doors which forms small enclosures for security reasons. U.S. Pat. No. 3,955,322 describes a single entry lock which may be swung from one side of a door frame to another. None of the prior art devices shows a security door which may be used in conjunction with a conventional door frame which has emergency opening features.